Dental hand-pieces of the type known as "contra-angle" tool holders generally include an elongated tubular housing arranged to be coupled at one end to the housing of a dental motor and enclosing an alley for a drive shaft which couples to the motor. At the other end the drive shaft is coupled to a tool shaft, or a tool clutch, through gears that rotate the tool on an axis transverse to the drive shaft axis, and a stub housing is provided to enclose the tool and the direction-changing gears. Typically of contra-angle tool holders, the stub-housing is provided with openings at both ends, one to receive the tool and the other to give access to mechanism to lock the tool in place. U.S. Pat. No. 3,369,298 shows one example of such contra-angle tool holders; in that example a clutch is permanently rotatably fixed in the stub housing, and a tool can be removably inserted into the clutch from one end, while a lock mechanism is provided at the other end. In other examples of such contra-angles, the tool is inserted through the housing from the lock-end of the stub housing, and a removable (e.g: threaded) cap is provided at the same end to perform the lock function. As contra angles are made smaller, these parts, especially removable caps, become so small that they are difficult to manipulate and are easily lost, wasting the time of the dentist. The housing structure required to provide a shaft alley for the drive shaft, communicating at an end with a transverse passage across the shaft alley for the tool or the clutch, are expensive to make, particularly in the smaller sizes. The choices of manufacturing process that can be used to make them are limited to processes that are suitable for making rigid tubular parts out of materials that are suitable for dental use, to precision standards.